allow_nil: false does not work from rails console - ruby-on-rails

Question

Newbie here, trying to add some rules to a ruby on rails form, specifically I don't want to allow the creation of an item if this has not a name
class Idea < ActiveRecord::Base
mount_uploader :picture, PictureUploader
belongs_to :project
validates :name, presence: true, allow_nil: false
end
Works smoothly if I create a new item from my app, but not happens the same if I create one item from rails console. How can I avoid the creation of an item without name, no matter if this has been created in the app or in the rails console?

Answer 1

The problem is you have to set allow_blank: false instead of allow_nil: false.
In Ruby an empty string is not nil.
"".nil?
#=> false
"".blank?
#=> true
Update your model like this
class Idea < ActiveRecord::Base
mount_uploader :picture, PictureUploader
belongs_to :project
validates :name, presence: true, allow_blank: false
end
If you want know the differences between nil and blank,see this SO post.
Refer these Guides for allow_blank

Answer 2

Try this from console:-
Idea.create(:name => "Something")
Rails console output:-
1.9.3-p385 :005 > c = CabinNumber.create(:name => "Something")
(0.2ms) begin transaction
SQL (1.1ms) INSERT INTO "cabin_numbers" ("created_at", "name", "status", "updated_at") VALUES (?, ?, ?, ?) [["created_at", Sun, 25 May 2014 00:02:04 IST +05:30], ["name", "Something"], ["status", false], ["updated_at", Sun, 25 May 2014 00:02:04 IST +05:30]]
(139.6ms) commit transaction
=> #<CabinNumber id: 11, name: "Something", status: false, created_at: "2014-05-24 18:32:04", updated_at: "2014-05-24 18:32:04">
OR
idea = Idea.new(:name => "hello")
idea.save
Rails console output:-
1.9.3-p385 :007 > c = CabinNumber.new(:name => "hello")
=> #<CabinNumber id: nil, name: "hello", status: false, created_at: nil, updated_at: nil>
1.9.3-p385 :008 > c.save
(0.1ms) begin transaction
SQL (1.0ms) INSERT INTO "cabin_numbers" ("created_at", "name", "status", "updated_at") VALUES (?, ?, ?, ?) [["created_at", Sun, 25 May 2014 00:02:57 IST +05:30], ["name", "hello"], ["status", false], ["updated_at", Sun, 25 May 2014 00:02:57 IST +05:30]]
(155.0ms) commit transaction
=> true
Cannot create if name field is not provided
1.9.3-p385 :003 > c = CabinNumber.create()
(0.2ms) begin transaction
(0.1ms) rollback transaction
=> #<CabinNumber id: nil, name: nil, status: false, created_at: nil, updated_at: nil>